June 15-21, 2010
Midwest Weekly Highlights - June 15-21, 2010
Severe Thunderstorms Pound Midwest
Severe thunderstorms battered the Midwest during the third week of June. Four fatalities and more than 700 damage reports were reported during the week (Figure 1). Despite the widespread storms, rainfall totals varied considerably with the central part of the region getting more than an inch above normal but surrounding areas were mostly below normal (Figure 2). More than 200 daily precipitation records were set.
The heavy rain across the middle of the region worsened flooding from Iowa and Missouri to Indiana (Figure 3). Flash flooding was also a problem in these areas. Southern Missouri experienced a dry week and the Upper Midwest saw little relief from its long-term drought (Figure 4).
Warm Across the Region
The Midwest was warm during the week. Temperatures ranged from just above normal in parts of Iowa and Minnesota to more than 7°F above normal in southern Missouri (Figure 5). Daily highs averaged 85°F to 95°F in the southern half of the region (Figure 6). Daily temperature records were scattered throughout the week.
Deadly Tornado Outbreak in Minnesota and North Dakota
A low pressure system and a leading warm front moved into Minnesota on June 17th (Figure 7) bringing deadly weather as more than a dozen tornadoes struck the state. Included were three EF4 tornadoes, the strongest Minnesota twisters in nearly ten years (July 25, 2000) and the most EF4 or stronger on one day in the state since April 30th, 1967. Deaths were attributed to three separate tornadoes near Almora (Otter Tail County), Mentor (Polk County), and Armstrong (Freeborn County). The Minnesota Climatology Group provides more details on the outbreak. Minnesota declared a State of Emergency in seven counties due to the devastating damage (Faribault, Freeborn, Olmstead, Otter Tail, Polk, Steele, and Wadena Counties). Access to entire towns and roads, including I-35 briefly, were restricted because of storm damage. Radar images from Thursday afternoon show the storms and weather warnings in northwest (Figure 8) and southern Minnesota (Figure 9). Hail up to 4.25 inches in diameter was reported in Douglas County, Minnesota along with 2.50 to 2.75 inch hail in Minnesota (Cass, Renville, and Sherburne Counties) and Kossuth County, Iowa.
Fatality in Indiana During June 18th Storms
June 18th brought more severe weather to the Midwest with storms extending from west to east across the central part of the region (Figure 10). A man died in Huntington County, Indiana on Friday evening when a tree fell onto his car. A church in Yeoman, Indiana (Carroll County) which was damaged by a tornado earlier this year, took on further damage when thunderstorm winds tore off the roof.
Winds were reported in excess of 75 miles per hour in Iowa, Illinois, Wisconsin, Michigan, and Indiana. Hundreds of wind damage reports were filed with damage to trees and power lines as well as structural damage to buildings. In downtown Chicago, Illinois (Cook County) windows in the 110-story Willis Tower were blown out as pebbles from other roofs were picked up in the strong winds. In the city of Chicago, an estimated 1,600 trees were damaged. Power outages Friday numbered 27,000 in Wisconsin, 180,000 in southern Michigan, and 550,000 in northeast Illinois with thousands still waiting for power to be restored on Sunday.
More Severe Weather
The week began with thunderstorms along the Ohio River on the 15th (Figure 11). Wind and hail was reported across Kentucky and the southern halves of Illinois, Indiana, and Ohio. Hail up to 2.25 inches was reported in Madison County, Illinois. Thunderstorm winds blew down trees and power lines across the four state region. There were also scattered reports of damage to buildings. In Grant County, Kentucky winds peaked at over 80 miles per hour.
Strong thunderstorms hit Missouri on the 19th (Figure 12) with winds up to 70 miles per hour. Damage was reported across Missouri to trees and power lines. Homes were also damaged and several trailer homes near Lake Contrary (Buchanan County) were destroyed.
On the 21st (Figure 13), several tornadoes were reported along with some golf ball sized hail and numerous reports of wind damage across several states. A lot of the damage was to trees, some of which blocked roads, and power lines. In southern Wisconsin, 48,000 customers lost power and several homes in Waukesha County were destroyed by a tornado.
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